A history of human-like dieting alters serotonergic control of feeding and neurochemical balance in a rat model of binge-eating.

OBJECTIVE

This study replicated a model of stress-induced binge-eating in rats with a history of caloric restriction (HCR), tested their response to SSRI (fluoxetine) treatment, and explored changes in brain monoamine levels.

METHOD

Young female rats with no-HCR/no-Stress, no-HCR/Stress, HCR/no-Stress, and HCR+Stress (binge-eating) were treated with fluoxetine. Post-mortem levels of serotonin, dopamine, and metabolites were assessed from brain regions key to feeding and reward.

RESULTS

A 3 mg/kg dose of fluoxetine without effect in the no-HCR groups suppressed intake of HCR groups, normalizing the binge-eating of HCR/Stress rats. No differences in monoamines were detected in the hypothalamus or tegmentum but a strong positive relationship between accumbens serotonin and dopamine turnover in no-HCR rats was absent in rats with HCR.

CONCLUSION

Despite lack of hunger, a history of human-like dieting alters serotonin function in ways suggesting consequences not only to feeding but also control of reward and mood that are dependent on dopamine/serotonin interactions.